The Astrophysical Journal最新文献_第3页

The Massive and Distant Clusters of WISE Survey 2: Second Data Release WISE 勘测 2 的大规模遥远星团：第二次数据发布

The Astrophysical Journal Pub Date : 2024-11-22 DOI: 10.3847/1538-4357/ad888c

Khunanon Thongkham, Anthony H. Gonzalez, Mark Brodwin, Ariane Trudeau, Peter Eisenhardt, S. A. Stanford, Emily Moravec, Thomas Connor, Daniel Stern, Ryan Spivey and Karolina Garcia

{"title":"The Massive and Distant Clusters of WISE Survey 2: Second Data Release","authors":"Khunanon Thongkham, Anthony H. Gonzalez, Mark Brodwin, Ariane Trudeau, Peter Eisenhardt, S. A. Stanford, Emily Moravec, Thomas Connor, Daniel Stern, Ryan Spivey and Karolina Garcia","doi":"10.3847/1538-4357/ad888c","DOIUrl":"https://doi.org/10.3847/1538-4357/ad888c","url":null,"abstract":"We present the second data release of the Massive and Distant Clusters of WISE Survey 2 (MaDCoWS2). We expand from the equatorial first data release to most of the Dark Energy Camera Legacy Survey area, covering a total area of 6498 deg2. The catalog consists of 133,036 signal-to-noise ratio (S/N) ≥ 5 galaxy cluster candidates at 0.1 ≤ z ≤ 2, including 6790 candidates at z > 1.5. We train a convolutional neural network (CNN) to identify spurious detections and include CNN-based cluster probabilities in the final catalog. We also compare the MaDCoWS2 sample with literature catalogs in the same area. The larger sample provides robust results that are consistent with our first data release. At S/N ≥ 5, we rediscover 59%–91% of clusters in existing catalogs that lie in the unmasked area of MC2. The median positional offsets are under 250 kpc, and the standard deviation of the redshifts is 0.031(1 + z). We fit a redshift-dependent power law to the relation between MaDCoWS2 S/N and observables from existing catalogs. Over the redshift ranges where the surveys overlap with MaDCoWS2, the lowest scatter is found between S/N and observables from optical/infrared surveys. We also assess the performance of our method using a mock light cone measuring purity and completeness as a function of cluster mass. The purity is above 90%, and we estimate the 50% completeness threshold at a virial mass of log(M/M⊙) ≈ 14.3. The completeness estimate is uncertain due to the small number of massive halos in the light cone, but consistent with the recovery fraction found by comparing to other cluster catalogs.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"181 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Luminosity Function of Collapsar Gamma-Ray Bursts: The Progenitor of Long Gamma-Ray Bursts Is Not Singular 坍缩伽玛射线暴的光度函数：长伽马射线暴的原生体不是单一的

The Astrophysical Journal Pub Date : 2024-11-21 DOI: 10.3847/1538-4357/ad88e7

Yan-Kun Qu, 艳坤屈, Zhong-Xiao Man, Shuang-Xi Yi, 双喜仪, Yu-Peng Yang and 玉鹏杨

{"title":"Luminosity Function of Collapsar Gamma-Ray Bursts: The Progenitor of Long Gamma-Ray Bursts Is Not Singular","authors":"Yan-Kun Qu, 艳坤屈, Zhong-Xiao Man, Shuang-Xi Yi, 双喜仪, Yu-Peng Yang and 玉鹏杨","doi":"10.3847/1538-4357/ad88e7","DOIUrl":"https://doi.org/10.3847/1538-4357/ad88e7","url":null,"abstract":"Gamma-ray bursts (GRBs) are powerful probes of the high-redshift Universe. However, the proportion of collapsar GRBs among long GRBs and their event rate relative to the star formation rate (SFR) remain contentious issues. We assume that long GRBs with z ≥ 2 are all collapsar GRBs and construct the luminosity function using a high-redshift sample from the Swift satellite spanning 2004 to 2019. We model the luminosity function with a broken power-law form and consider three scenarios: no evolution, luminosity evolution, and density evolution. Our results are as follows: (1) The no-evolution model can be ruled out. (2) The fitting results indicate that to adequately explain the observations, a significant redshift evolution in either luminosity (evolution index ) or density ( ) is required. This excludes the possibility that the evolution of long GRBs with redshift is due to contamination from noncollapsar GRBs. (3) The luminosity evolution model predicts that the number of collapsar GRBs with z < 2 and P ≥ 1 ph cm−2 s−1 is 138.6, accounting for 82.5% of the observed long GRBs with z < 2 and P ≥ 1 ph cm−2 s−1. The density evolution model predicts that the number of collapsar GRBs with z < 2 and P ≥ 1 ph cm−2 s−1 is 80.2, accounting for 47.7% of the observation. Regardless of the model, a substantial portion of the long GRBs are not collapsar GRBs.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Velocity-resolved Reverberation Mapping of Changing-look Active Galactic Nucleus NGC 4151 during Outburst Stage. II. Results of Four Seasons of Observation 爆发期变化外观活动星系核 NGC 4151 的速度分辨混响绘图。II.四季观测结果

The Astrophysical Journal Pub Date : 2024-11-21 DOI: 10.3847/1538-4357/ad8568

Hai-Cheng Feng, Sha-Sha Li, J. M. Bai, H. T. Liu, Kai-Xing Lu, Yu-Xuan Pang, Mouyuan Sun, Jian-Guo Wang, Yang-Wei Zhang and Shuying Zhou

{"title":"Velocity-resolved Reverberation Mapping of Changing-look Active Galactic Nucleus NGC 4151 during Outburst Stage. II. Results of Four Seasons of Observation","authors":"Hai-Cheng Feng, Sha-Sha Li, J. M. Bai, H. T. Liu, Kai-Xing Lu, Yu-Xuan Pang, Mouyuan Sun, Jian-Guo Wang, Yang-Wei Zhang and Shuying Zhou","doi":"10.3847/1538-4357/ad8568","DOIUrl":"https://doi.org/10.3847/1538-4357/ad8568","url":null,"abstract":"We present the results of a four-year velocity-resolved reverberation mapping (RM) campaign of the changing-look active galactic nucleus (CL-AGN) NGC 4151 during its outburst phase. By measuring the time lags of the Hα, Hβ, Hγ, He i, and He ii emission lines, we confirm a stratified broad-line region (BLR) structure that aligns with predictions from photoionization models. Intriguingly, we observed an “anti-breathing” phenomenon, where the lags of broad emission lines decreased with increasing luminosity, contrary to the typical expectation. This anomaly may be attributed to the influence of the ultraviolet-optical lag or nonvirialized motions in the BLR gas. Velocity-resolved RM and ionization mapping analyses revealed rapid and significant changes in the BLR geometry and kinematics on timescales of less than a year, which cannot be interpreted by any single mechanism, such as an inhomogeneous BLR, variations in radiation pressure, or changes in the illuminated ionizing field. Additionally, the Hβ lags of NGC 4151 and other CL-AGNs agree with the radius–luminosity relationship established for AGNs with low accretion rates, implying that the CL phenomenon is more likely driven by intrinsic changes in the accretion rate rather than obscuration. These findings provide new insights into the complex internal processes of CL-AGNs and highlight the importance of long-term, multiline RM for understanding BLR structures, geometry, and kinematics.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Probing the Morphology of Polarized Emission Induced by Fluctuation Dynamo Using Minkowski Functionals 利用闵科夫斯基函数探测波动动力诱导的极化发射形态

The Astrophysical Journal Pub Date : 2024-11-21 DOI: 10.3847/1538-4357/ad891c

Riju Dutta, Sharanya Sur and Aritra Basu

{"title":"Probing the Morphology of Polarized Emission Induced by Fluctuation Dynamo Using Minkowski Functionals","authors":"Riju Dutta, Sharanya Sur and Aritra Basu","doi":"10.3847/1538-4357/ad891c","DOIUrl":"https://doi.org/10.3847/1538-4357/ad891c","url":null,"abstract":"The morphology and the characteristic scale of polarized structures provide crucial insights into the mechanisms that drive turbulence and maintain magnetic fields in magneto-ionic plasma. We aim to establish the efficacy of Minkowski functionals as quantitative statistical probes of filamentary morphology of polarized synchrotron emission resulting from fluctuation dynamo action. Using synthetic observations generated from magnetohydrodynamic simulations of fluctuation dynamos with varying driving scales (ℓf) of turbulence in isothermal, incompressible, and subsonic media, we study the relation between different morphological measures and their connection to fractional polarization (pf). We find that Faraday depolarization at low frequencies gives rise to small-scale polarized structures that have higher filamentarity as compared to the intrinsic structures that are comparable to ℓf. Above ∼3 GHz, the number of connected polarized structures per unit area (NCC,peak) is related to the mean pf (〈pf〉) of the emitting region as , provided the scale of the detectable emitting region is larger than ℓf. This implies that NCC,peak represents the number of turbulent cells projected on the plane of the sky and can be directly used to infer ℓf via the relation . An estimate of ℓf thus directly allows for pinning down the turbulence-driving mechanism in astrophysical systems. While the simulated conditions are mostly prevalent in the intracluster medium of galaxy clusters, the qualitative morphological features are also applicable in the context of interstellar medium in galaxies.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Reflected-light Phase Curves with PICASO: A Kepler-7b Case Study PICASO 的反射光相位曲线：开普勒-7b 案例研究

The Astrophysical Journal Pub Date : 2024-11-21 DOI: 10.3847/1538-4357/ad7de6

Colin D. Hamill, Alexandria V. Johnson, Natasha Batalha, Rowan Nag, Peter Gao, Danica Adams and Tiffany Kataria

{"title":"Reflected-light Phase Curves with PICASO: A Kepler-7b Case Study","authors":"Colin D. Hamill, Alexandria V. Johnson, Natasha Batalha, Rowan Nag, Peter Gao, Danica Adams and Tiffany Kataria","doi":"10.3847/1538-4357/ad7de6","DOIUrl":"https://doi.org/10.3847/1538-4357/ad7de6","url":null,"abstract":"Examining reflected light from exoplanets aids in our understanding of the scattering properties of their atmospheres and will be a primary task of future flagship space- and ground-based telescopes. We introduce an enhanced capability of Planetary Intensity Code for Atmospheric Scattering Observations (PICASO), an open-source radiative transfer model used for exoplanet and brown dwarf atmospheres, to produce reflected light phase curves from three-dimensional atmospheric models. Since PICASO is coupled to the cloud code Virga, we produce phase curves for different cloud condensate species and varying sedimentation efficiencies (fsed) and apply this new functionality to Kepler-7b, a hot Jupiter with phase curve measurements dominated by reflected starlight. We model three different cloud scenarios for Kepler-7b: MgSiO3 clouds only, Mg2SiO4 clouds only, and Mg2SiO4, Al2O3, and TiO2 clouds. All our Virga models reproduce the cloudy region west of the substellar point expected from previous studies, as well as clouds at high latitudes and near the eastern limb, which are primarily composed of magnesium silicates. Al2O3 and TiO2 clouds dominate near the substellar point. We then compare our modeled reflected light phase curves to Kepler observations and find that models with all three cloud condensate species and low sedimentation efficiencies (0.03–0.1) match best, though our reflected light phase curves show intensities approximately one-third of those observed by Kepler. We conclude that a better understanding of zonal transport, cloud radiative feedback, and particle scattering properties is needed to further explain the differences between the modeled and observed reflected light fluxes.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Self-consistent Model of Shock-heated Plasma in Nonequilibrium States for Direct Parameter Constraints from X-Ray Observations 非平衡态冲击加热等离子体的自洽模型，用于从 X 射线观测中获得直接参数约束

The Astrophysical Journal Pub Date : 2024-11-21 DOI: 10.3847/1538-4357/ad822d

Yuken Ohshiro, Shunsuke Suzuki, Yoshizumi Okada, Hiromasa Suzuki and Hiroya Yamaguchi

{"title":"A Self-consistent Model of Shock-heated Plasma in Nonequilibrium States for Direct Parameter Constraints from X-Ray Observations","authors":"Yuken Ohshiro, Shunsuke Suzuki, Yoshizumi Okada, Hiromasa Suzuki and Hiroya Yamaguchi","doi":"10.3847/1538-4357/ad822d","DOIUrl":"https://doi.org/10.3847/1538-4357/ad822d","url":null,"abstract":"X-ray observations of shock-heated plasmas, such as those found in supernova remnants (SNRs), often exhibit features of temperature and ionization nonequilibrium. For accurate interpretation of these observations, proper calculations of the equilibration processes are essential. Here, we present a self-consistent model of thermal X-ray emission from shock-heated plasmas that accounts for both temperature and ionization nonequilibrium conditions. For a given pair of shock velocity and initial electron-to-ion temperature ratio, the temporal evolution of the temperature and ionization state of each element was calculated by simultaneously solving the relaxation processes of temperature and ionization. The resulting thermal X-ray spectrum was synthesized by combining our model with the AtomDB spectral code. Comparison between our model and the nei model, a constant-temperature nonequilibrium ionization model available in the XSPEC software package, reveals a 30% underestimation of the ionization timescale in the nei model. We implemented our model in XSPEC to directly constrain the shock wave’s properties, such as the shock velocity and collisionless electron heating efficiency, from the thermal X-ray emission from postshock plasmas. We applied this model to archival Chandra data of the SNR N132D, providing a constraint on the shock velocity of ∼800 km s−1, in agreement with previous optical studies.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Quasi-linear Analysis of Proton-cyclotron Instability 质子-环子不稳定性的准线性分析

The Astrophysical Journal Pub Date : 2024-11-21 DOI: 10.3847/1538-4357/ad86be

Peter H. Yoon, Rodrigo A. López, Jungjoon Seough, Muhammad Rashid, Chadi S. Salem, Muhammad Sarfraz, Marian Lazar and Shaaban M. Shaaban

{"title":"Quasi-linear Analysis of Proton-cyclotron Instability","authors":"Peter H. Yoon, Rodrigo A. López, Jungjoon Seough, Muhammad Rashid, Chadi S. Salem, Muhammad Sarfraz, Marian Lazar and Shaaban M. Shaaban","doi":"10.3847/1538-4357/ad86be","DOIUrl":"https://doi.org/10.3847/1538-4357/ad86be","url":null,"abstract":"The proton-cyclotron (PC) instability operates in various space plasma environments. In the literature, the so-called velocity moment-based quasi-linear theory is employed to investigate the physical process of PC instability that takes place after the onset of early linear exponential growth. In this method, the proton velocity distribution function (VDF) is assumed to maintain a bi-Maxwellian form for all time, which substantially simplifies the analysis, but its validity has not been rigorously examined by comparing against the actual solution of the kinetic equation. The present paper relaxes the assumption of the velocity moment-based quasi-linear theory by actually solving for the velocity space diffusion equation under the assumption of separable perpendicular and parallel VDFs, and upon comparison with the simplified velocity moment theory, it demonstrates that the simplified method is largely valid, despite the fact that the method slightly overemphasizes the relaxation of temperature anisotropy when the system is close to the marginally stable state. The overall validation is further confirmed with the results of particle-in-cell and hybrid-code simulations. The present paper thus provides a justification for making use of the velocity moment-based quasi-linear theory as an efficient first-cut theoretical tool for the PC instability.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"252 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modeling the X-Ray Emission of the Boomerang Nebula and Implication for Its Potential Ultrahigh-energy Gamma-Ray Emission 回旋星云的 X 射线发射模型及其对潜在超高能伽马射线发射的影响

The Astrophysical Journal Pub Date : 2024-11-21 DOI: 10.3847/1538-4357/ad87d2

Xiao-Bin Chen, Xuan-Han Liang, Ruo-Yu Liu and Xiang-Yu Wang

{"title":"Modeling the X-Ray Emission of the Boomerang Nebula and Implication for Its Potential Ultrahigh-energy Gamma-Ray Emission","authors":"Xiao-Bin Chen, Xuan-Han Liang, Ruo-Yu Liu and Xiang-Yu Wang","doi":"10.3847/1538-4357/ad87d2","DOIUrl":"https://doi.org/10.3847/1538-4357/ad87d2","url":null,"abstract":"The Boomerang Nebula is a bright radio and X-ray pulsar wind nebula (PWN) powered by an energetic pulsar, PSR J2229+6114. It is spatially coincident with one of the brightest ultrahigh-energy (UHE; ≥100 TeV) gamma-ray sources, LHAASO J2226+6057. While X-ray observations have provided radial profiles for both the intensity and photon index of the nebula, previous theoretical studies have not reached an agreement on their physical interpretation, which also leads to different anticipation of the UHE emission from the nebula. In this work, we model its X-ray emission with a dynamical evolution model of PWN, considering both convective and diffusive transport of electrons. On the premise of fitting the X-ray intensity and photon index profiles, we find that the magnetic field within the Boomerang Nebula is weak (∼10 μG in the core region and diminishing to 1 μG at the periphery), which therefore implies a significant contribution to the UHE gamma-ray emission by the inverse Compton (IC) radiation of injected electron/positron pairs. Depending on the particle transport mechanism, the UHE gamma-ray flux contributed by the Boomerang Nebula via the IC radiation may constitute about 10%–50% of the flux of LHAASO J2226+6057 at 100 TeV and up to 30% at 500 TeV. Finally, we compare our results with previous studies and discuss potential hadronic UHE emission from the PWN. In our modeling, most of the spindown luminosity of the pulsar may be transformed into thermal particles or relativistic protons.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"2 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The SPT-Chandra BCG Spectroscopic Survey. I. Evolution of the Entropy Threshold for ICM Cooling and AGN Feedback in Galaxy Clusters over the Last 10 Gyr SPT-Chandra BCG 光谱巡天。I. 过去 10 Gyr 银河系星团中 ICM 冷却和 AGN 反馈的熵阈值演变

The Astrophysical Journal Pub Date : 2024-11-21 DOI: 10.3847/1538-4357/ad8916

Michael S. Calzadilla, Michael McDonald, Bradford A. Benson, Lindsey E. Bleem, Judith H. Croston, Megan Donahue, Alastair C. Edge, Benjamin Floyd, Gordon P. Garmire, Julie Hlavacek-Larrondo, Minh T. Huynh, Gourav Khullar, Ralph P. Kraft, Brian R. McNamara, Allison G. Noble, Charles E. Romero, Florian Ruppin, Taweewat Somboonpanyakul and G. Mark Voit

{"title":"The SPT-Chandra BCG Spectroscopic Survey. I. Evolution of the Entropy Threshold for ICM Cooling and AGN Feedback in Galaxy Clusters over the Last 10 Gyr","authors":"Michael S. Calzadilla, Michael McDonald, Bradford A. Benson, Lindsey E. Bleem, Judith H. Croston, Megan Donahue, Alastair C. Edge, Benjamin Floyd, Gordon P. Garmire, Julie Hlavacek-Larrondo, Minh T. Huynh, Gourav Khullar, Ralph P. Kraft, Brian R. McNamara, Allison G. Noble, Charles E. Romero, Florian Ruppin, Taweewat Somboonpanyakul and G. Mark Voit","doi":"10.3847/1538-4357/ad8916","DOIUrl":"https://doi.org/10.3847/1538-4357/ad8916","url":null,"abstract":"We present a multiwavelength study of the brightest cluster galaxies (BCGs) in a sample of the 95 most massive galaxy clusters selected from the South Pole Telescope Sunyaev–Zeldovich (SZ) survey. Our sample spans a redshift range of 0.3 < z < 1.7, and is complete with optical spectroscopy from various ground-based observatories, as well as ground and space-based imaging from optical, X-ray, and radio wave bands. At z ∼ 0, previous studies have shown a strong correlation between the presence of a low-entropy cool core and the presence of both star formation and radio-loud active galactic nuclei in the central BCG. We show for the first time that the central entropy threshold for triggering star formation, which is universally seen in nearby systems, persists out to z ∼ 1, with only marginal (∼1σ) evidence for evolution in the threshold entropy value itself. In contrast, we do not find a similar high-z analog for an entropy threshold for feedback, but instead measure a strong evolution in the fraction of radio-loud BCGs in high-entropy cores, decreasing with increasing redshift. This could imply that the cooling-feedback loop was not as tight in the past, or that some other fuel source like mergers are fueling the radio sources more often with increasing redshift, making the radio luminosity an increasingly unreliable proxy for radio jet power. We also find that our SZ-based sample is missing a small (∼4%) population of the most luminous radio sources (νLν > 1042 erg s−1), likely due to radio contamination suppressing the SZ signal with which these clusters are detected.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Near-infrared Spectroscopy of the Sun and Solar Analog Star HD 76151: Compiling an Extensive Line List in the Y, J, H, and K Bands 太阳和太阳类似星 HD 76151 的近红外光谱：编制Y、J、H和K波段的大量谱线列表

The Astrophysical Journal Pub Date : 2024-11-21 DOI: 10.3847/1538-4357/ad85e4

Sena Aleyna Şentürk, Timur Şahin, Ferhat Güney, Selçuk Bilir and Mahmut Marışmak

{"title":"Near-infrared Spectroscopy of the Sun and Solar Analog Star HD 76151: Compiling an Extensive Line List in the Y, J, H, and K Bands","authors":"Sena Aleyna Şentürk, Timur Şahin, Ferhat Güney, Selçuk Bilir and Mahmut Marışmak","doi":"10.3847/1538-4357/ad85e4","DOIUrl":"https://doi.org/10.3847/1538-4357/ad85e4","url":null,"abstract":"Determining the physical nature of a star requires precise knowledge of its stellar atmospheric parameters, including effective temperature, surface gravity, and metallicity. This study presents a new atomic line list covering a broad spectral range (1–2.5 μm; YJHK bands) for iron (Fe) and α-elements (Ca, Mg, Ti, Si) to improve stellar parameter determination using near-infrared (NIR) spectroscopy. We highlight the limitations of existing line lists, stemming primarily from inconsistencies in oscillator strengths for ionized iron lines within the Apache Point Observatory Galactic Evolution Experiment DR17. The line list was validated using the high-resolution and high-quality disk-center NIR spectra of the Sun and its solar analog HD 76151. As a result of the spectroscopic analyses, the effective temperature of HD 76151 was calculated as 5790 ± 170 K, surface gravity as 4.35 ± 0.18 cgs, metal abundance as 0.24 ± 0.09 dex, and microturbulence velocity of km s−1 by combining the optical and NIR line lists. A comparison of the model atmospheric parameters calculated for HD 76151 with the PARSEC isochrones resulted in a stellar mass of , radius , and an age of Gyr. For the first time, kinematic and dynamical orbital analyses of HD 76151 using a combination of Gaia astrometric and spectroscopic data showed that the star was born in a metal-rich region within the solar circle and is a member of the thin disk population. Thus, the slightly metal-rich nature of the star, as reflected in its spectroscopic analysis, was confirmed by dynamical orbital analysis.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0